1. Field of the Invention
The present invention relates to a manufacturing method, and more particularly to a manufacturing method of a muffler assembly.
2. Description of Related Art
Conventional muffler assemblies are usually classified in one of the following types:
A. straight pipe type in which there are many muffler elements adhered on an inner periphery of the pipe;
B. tortuous pipe type using a tortuous pipe to increase the muffler area for providing the muffler effect;
C. swell type having a structure similar to that of the straight type, but with an enlarged portion to dissipate energy; and
D. resonance type in which there is a resonance chamber directed to certain acoustic frequencies to achieve the muffling objective.
A conventional muffler assembly comprises a casing having two holes defined in opposite ends of the casing. A corresponding one of the above muffler types is received in the casing via the two holes in the casing. An inlet pipe and an exhaust pipe are respectively inserted into a respective one of the two holes in the casing. The inlet pipe and the exhaust pipe are secured to the casing by welding. Most of the manufacturing processes of a conventional muffler assembly are welded such that the manufacturing processes are complicated, the work environment is bad and the manufacturing cost is difficult to reduce.
The present invention has been developed to mitigate and/or obviate the disadvantages of the conventional manufacturing method of a muffler assembly.
The main objective of the present invention is to provide an improved method for manufacturing a muffler assembly.
To achieve the objective, the manufacturing method in accordance with the invention comprises the following steps:
Step 1. a pipe is cut to a length slightly longer than that of a muffling device;
Step 2. the pipe has a lower end that is forged and formed as an exhaust pipe;
Step 3. a muffling device that is wound as a spiral is inserted in a middle portion of the pipe;
Step 4. the pipe has an upper end that is forged and formed as an inlet pipe; and
Step 5. the inlet pipe and the exhaust pipe are forged again to hold the muffling device in place in the middle portion of the pipe.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.